In the optoelectronics field, along with the trend for high performance of instruments, cases are increasing wherein bonding is carried out between various different materials as objects to be bonded, such as between glass materials, between glass and metal, between glass and ceramic, between glass and plastic, between plastics, between plastic and metal, and between plastic and ceramic. And, for bonding between such various different materials, an adhesive exhibiting a high bond strength and having good heat resistance and moisture resistance, is desired.
Particularly, in bonding between various different materials, an influence of an internal stress caused by e.g. a cure shrinkage of the adhesive over the respective objects to be bonded, is not negligible, and it is desired to develop an adhesive having a low cure shrinkage and little adhesion strain.
In such a trend of technology, adhesives in this field have been changed, taking mass production into consideration, from thermosetting epoxy adhesives to fast curing w-acrylic adhesives or epoxy adhesives.
For example, Patent Documents 1 and 2 disclose urethane acrylate w-curable liquid crystal sealing agents to seal liquid crystal panels; Patent Document 3 discloses an epoxy acrylate UV-curable liquid crystal sealing agent; and Patent Document 4 discloses an epoxy UV-curable adhesive. Further, Patent Document 5 proposes a waterproof adhesive composition having 2-hydroxyethyl methacrylate as one component, as an adhesive composition excellent in water resistance, and Patent Document 6 discloses an UV-curable composition suitable for bonding molded products made of a thermoplastic norbornene resin.
Patent Document 1: JP-A-7-13173
Patent Document 2: JP-A-7-13174
Patent Document 3: JP-A-7-13175
Patent Document 4: JP-A-7-118369
Patent Document 5: JP-A-1-207371
Patent Document 6: JP-A-7-138332